Funny...
That's not how they spell it on [link|http://www.northgrum.com/|[link|http://www.northgrum.com/|http://www.northgrum.com/]].
But then, you guyses variant really is incredibly frequent for a misspelling: A Google search for "Northrup Grumman" returned about 5,000 hits; "Northrop Grumman", about 60,500. Almost one in twelve; that must be exceptional.
Christian R. Conrad
The Man Who Knows Fucking Everything About Speling